This application claims the priority of Germany patent document 198 39 348.2, filed Aug. 28, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a vehicle security system have a remotely operable vehicle access unit.
Such security systems are used, for example, in cars, in order to allow access to and/or use of the vehicle only by authorized vehicle operators, who use the authentication elements to request desired control measures of the access monitoring device or of the electronic immobilizing device via a wireless actuation communication channel, and to verify themselves as authorized for this purpose. Actuation of the control part of the access monitoring device and/or of the electronic immobilizer on the vehicle side is carried out subject to authentication.
Electronic keys based on systems with mechanical keys are commonly used as authentication elements for such wireless actuation communication channels. (See, for example, German Patent Document DE 195 31 219 C1.) In this case, the term xe2x80x9celectronic keyxe2x80x9d should primarily be understood to mean those authentication elements which communicate without wires and in which action of the authentication element itself is required to carry out the authentication process. For example, a respective authentication communication process is initiated by operating a button or the like which is arranged on the electronic key, or by inserting the key in a key holder on the vehicle.
In order to avoid the need for the use of a key, so-called xe2x80x9ckeyless-goxe2x80x9d systems with associated actuation communication channels without keys have been increasingly proposed recently, for use in place of systems with electronic keys and the associated wireless actuation communication channels with a key. The term keyless-go systems in this case means those security systems in which the authentication element itself requires no special action to carry out the authentication communication processes. Smart cards and transponders are used, in particular, as authentication elements for such systems, which vehicle users need only carry with them. See, for example, B. Priemer, Kleines Wunderxe2x80x94Vorstellung Mercedes S-Klasse [Minor miraclexe2x80x94Introduction to the Mercedes S-Class], Auto Motor Sport, 15/1998, page 16.
Various procedures are known for the user to request a desired control measure using a keyless-go system. For example, there are systems in which an authentication communication is initiated automatically without any further action by the user when he or she enters the effective area of the relevant actuation communication channel, carrying an authentication element. (That is, enters the area in which communication processes can be carried out effectively between the authentication element and the security control part on the vehicle side). Alternatively, systems are known in which an authentication communication process takes place via a control element arranged in the vehicle, or via a voice input with a request from a user. See German Patent Documents DE 40 27 491 C2 and DE 44 14 734 C2.
One object of the invention is provide a vehicle security system of the type mentioned initially, which allows a high degree of convenience of use and for which a high level of acceptance can be expected.
This and other objects and advantages are achieved by the vehicle security system according to the invention, in which a keyless-go system is combined in an advantageous manner with a system based on electronic keys. With both subsystems thus provided in parallel, the user can optionally actuate the security system via the communication channel of the subsystem which operates with electronic keys, or via the communication channel of the keyless-go subsystem (which needs no key). By providing the option of being able to actuate the security system using electronic keys, it is possible to achieve a high level of acceptance, since such systems are already in widespread use. On the other hand, the present system offers the user the option of making use of the increased convenience of using a keyless-go system.
As a result of the special combination of the two subsystems which, in principle, gives the actuation communication channel with a key priority over the actuation communication channel without a key, the vehicle user does not himself or herself need to worry any more about any changeover between the two subsystems. In fact, in operation, the security system in principle accepts both the actuation commands initiated via the one actuation communication channel and those via the other actuation communication channel, at any time, and processes these commands using the above priority principle. This means that the actuation commands emitted via an electronic key are normally obeyed immediately, or in any case after a suitable delay, provided that the present vehicle situation allows, while an actuation command entered via the communication channel without a key is obeyed only if there is no actuation command from the subsystem with a key colliding with it.
One embodiment of the invention includes an advantageous type of prioritization for the vehicle locking function carried out by the associated access monitoring device. The chosen prioritization ensures that a user who is used to electronic keys can lock the vehicle, on leaving it, using his or her electronic key in the normal manner. The system obeys this request, even if there is any contradictory unlocking command via the keyless-go subsystem. This is useful in particular when the keyless-go subsystem automatically initiates appropriate locking or unlocking commands when an associated, valid authentication element is located in the effective area of the relevant actuation communication channel without a key.
According to another feature of the invention, the electronic immobilizing device includes a conventional key holder on the vehicle side, into which a valid electronic key can be introduced for the user to actuate the immobilizer. Thereafter, an authentication communication is carried out, generally automatically; if it is successful, the immobilizer is disarmed. In a development of this device, it is now proposed that the actuation communication channel without a key is kept deactivated for as long as an electronic key (identified as being valid) is located in the key holder. In consequence, a user who is used to electronic keys can, if he or she wants, operate the vehicle as usual with his or her key without being influenced by actions from the keyless-go subsystem. On the other hand, he or she can make use of the high level of convenience in use of the keyless-go subsystem by not introducing an electronic key into the key holder, but by carrying the authentication element of the keyless-go subsystem on his or her person.
Another embodiment of the invention offers an advantageous transitional measure from the keyless-go subsystem to the subsystem with a key while the vehicle is being operated. That is, once the user has introduced a valid electronic key into the key holder when the vehicle engine is running, and the key is in the ignition-off position, the engine is not switched off until the vehicle is stationary.
Finally, still another embodiment of the invention offers a high level of convenience in that both an electronic key and an authentication element which involves no action for the keyless-go subsystem are integrated into a common, combined authentication element. Each authorized system user then needs to carry only a single authentication element with him or her, which can be used both as an electronic key and as a keyless-go authentication element which involves no action.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.